1. Field of the Invention:
This invention relates to fluid valves and more specifically to seal means for gate-type fluid valves.
2. Description of the Prior Art:
Heretofore, various gate-type fluid valves have been developed. Many of these valves have gates and seats made of ceramic material for reducing the wear and erosion thereof. While such gates and seats do reduce the wear and erosion thereof, they are very susceptible to breakage and fracture caused by the high pressure exerted thereon by the fluid. Typically, a seal member such as a standard O-ring or the like is placed between each seat and the valve housing to prevent any fluid from incorrectly passing between the seats and the valve housing so as to prevent improper and incorrect escapage or passage of fluid through the valve especially when the valve is closed. These O-rings are tightly inserted between each seat and the valve housing in such a manner that the O-rings are non-movable and prevent at all times any and all flow or passage of fluid between the valve housing and the seats. While these seal members accomplish a necessary function, they cause unequal pressure and stress to be exerted on different sides or portions of the gate and seats which often results in fracture or breakage of the gate and/or seats.